The present inventive concept relates to plasma processing apparatus.
A plasma processing apparatus is commonly used for manufacturing semiconductor devices, Light Emitting Diodes (LED), Liquid Crystal Displays (LCD), or the like. Thereamong, an ICP-type etching apparatus includes a hole in the center of a window plate, an RF Power transmission path, and a nozzle mounted in the hole to inject a process gas into a chamber. A process gas is excited to a plasma state inside the chamber and collides with an etching target (for example, a wafer) to perform an etching process.
Here, a hole peripheral region of the window plate including the nozzle is structurally vulnerable, as compared to a different region of the window plate, thereby leading to particulation due to plasma damage. Particularly, when the window plate is reused after having been cleaned by a chemical cleaning agent or after having been polished, the hole peripheral region of the window plate may be exposed to plasma to accelerate degradation thereof, and thus, the hole peripheral region is vulnerable to particulation. In addition, a service life of window plate may be limited according to the number of washes thereof.
Generally, a process gas is injected through a nozzle in a vertical direction, and a mixture momentum of the process gas is less in a lower pressure region inside a chamber, which may lead to non-uniform distribution of a process gas in a wafer edge region. Therefore, a problem such as a product yield decrease or the like may be caused.